首页
登录
职称英语
In 1995 the Galileo spacecraft captured data about Jupiter’s atmosphere--- namel
In 1995 the Galileo spacecraft captured data about Jupiter’s atmosphere--- namel
游客
2024-01-10
42
管理
问题
In 1995 the Galileo spacecraft captured data about Jupiter’s atmosphere--- namely, the absence of most of the predicted atmospheric water--- that challenged prevailing theories about Jupiter’s structure. The unexpectedness of this finding fits a larger pattern in which theories about planetary composition and dynamics have failed to predict the realities discovered through space exploration. Instead of “normal planets” whose composition could be predicted by theory, the planets populating our solar system are unique individuals whose chemical and tectonic identities were created through numerous contingent events. One implication of this is that although the universe undoubtedly holds other planetary systems, the duplication of the sequence that produced our solar system and the development of life on Earth is highly unlikely.
Recently planetary scientists have suggested that the external preconditions for the development of Earth’s biosphere probably included four paramount contingencies. First, a climate conducive to life on earth depends upon the extraordinarily narrow orbital parameters that define a continuously habitable zone where water can exist in a liquid state. If Earth’s orbit were only 5 percent smaller than it is, temperatures during the early stages of Earth’s history would have been high enough to vaporize the oceans. If the Earth-Sun distance were as little as 1 percent larger, runaway glaciations on Earth about 2 billion years ago would have caused the oceans to freeze and remain frozen to this day.
Second, Jupiter’s enormous mass prevents most Sun-bound comets from penetrating the inner solar system. It has been estimated that without this shield, Earth would have experienced bombardment by comet-sized impactors a thousand times more frequently than has actually been recorded during geological time. Even if Earth’s surface were not actually sterilized by this bombardment, it is unlikely that any but the most primitive life-forms could have survived. This suggests that only planetary system containing both terrestrial planets like Earth and gas giants like Jupiter might be capable of sustaining complex life-forms.
Third, the gravitational shield of the giant outer planets, while highly efficient, must occasionally fail to protect Earth. Paradoxically, while the temperatures required for liquid water exist only in the inner solar system, the key building blocks of life, including water itself, occur primarily beyond the asteroid belt. Thus the evolution of life has depended on a frequency of cometary impacts sufficient to convey water, as well as carbon and nitrogen, from these distant regions of the solar system to Earth while stopping short of an impact magnitude that would destroy the atmosphere and oceans.
Finally, Earth’s unique and massive satellite, the Moon, plays a crucial role in stabilizing the obliquity of Earth’s rotational axis. This obliquity creates the terrestrial seasonality so important to the evolution and diversity of life. Mars, in contrast, has a wildly oscillating tilt and chaotic seasonality, while Venus, rotating slowly backward, has virtually no seasonality at all. [br] The author of the passage most likely mentions Mars’ “oscillating tilt” primarily in order to
选项
A、Provide evidence for a proposition about the potential effects of cometary impacts
B、Emphasize the absence from our solar system of “normal planets”
C、Contrast the rotational axis of Mars with that of Venus.
D、Characterize the role of other planets in the solar system in earth’s development.
E、Emphasize the importance of the Moon to the development of life on Earth.
答案
E
解析
本题为句子功能题,正确答案为定位句的3s版本。本题定位到最后一段第二句,火星倾角在这段中只是一个用于衬托月亮重要性的例子。因此E正确。
转载请注明原文地址:http://tihaiku.com/zcyy/3350503.html
相关试题推荐
ItmaybeanotherfifteenyearsbeforespacecraftfromEarthagainventuretoMa
AlthoughjustinsidetheorbitofJupiter,amateurastronomerswithgoodtelesco
ThecamerasoftheVoyagerIIspacecraftdetectedsixsmall,previouslyunseenm
Tosurvive,anon-humanspeciesmustbetoo______tobethoroughlycaptured,too
BecausetheyhadexpectedthespacecraftVoyager2tobeabletogatherdataonl
Metis,theinnermost______ofJupiter,completesafullrevolutionaroundthisgi
In1995theGalileospacecraftcaptureddataaboutJupiter’satmosphere---namel
In1995theGalileospacecraftcaptureddataaboutJupiter’satmosphere---namel
In1995theGalileospacecraftcaptureddataaboutJupiter’satmosphere---namel
AlthoughJungiusdetectedGalileo’s(i)____inthinkingthatthecurveassumedb
随机试题
Modernindustrialsocietygrantslittlestatustooldpeople.Infact,such
脚手架搭设施工中,以下正确的是()。A.脚手架应按规定采用连接件与构筑物相
沥青混合料摊铺机必须缓慢、均匀、连续不间断地摊铺,当发现沥青混合料面层出现明显的
设(X1,X2,…,X10)是抽自正态总体N( )的一个容量为10的样本,
关于单栋建筑中的综合布线,下列叙述中( )是不正确的:A.单栋建筑中的综合布线
小儿上呼吸道感染的常见兼夹证是A.夹痰、夹滞、夹惊 B.夹湿、夹惊、夹滞 C
朱砂的用法是A.打碎先煎 B.冲服 C.包煎 D.烊化 E.后下
在建设工程进度计划执行过程中,当出现的进度偏差影响到后续工作或总工期而需要采取进
用计划期的任务量和物品的消耗定额来确定物品需要量的方法是( )。 A.间接
根据科尔伯格的道德发展阶段论,遵守法规和秩序定向阶段是儿童道德判断的第()阶段。
最新回复
(
0
)